US3720112A - Load limiter for self-energizing drive - Google Patents

Abstract

A load limiter for a self-energizing drive mechanism which has a rotating disk, a wheel driven therefrom and a swing mechanism on which the wheel is swung toward and away from the disk, said limiter comprising stop means for limiting swinging motion of the swing mechanism toward the disk and yieldable spring biased mounting means for the disk on which the disk will yield prior to engagement of the stop means, whereby the pressure between the wheel and disk is limited to the spring bias of the disk mounting means.

Description

United States Patent [191 Enters et a1.

mlMarch 13, 1973 LOAD LIMITER FOR SELF- ENERGIZING DRIVE [75] Inventors: Edward W. Enters, Fredonia; Warren H. Price, Sheboygan, both of Wis.

[73] Assignee: Gilson Bros. Co., Plymouth, Wis.

[22] Filed: Oct. 22, 1971 [21] Appl. No.: 191,646

[52] US. Cl ..74/l96, 74/202 [51] Int. Cl. ..F16h 15/08, Fl6h 13/02 [58] Field of Search ..74/l96, 199, 194, 202

[ 56] References Cited UNITED STATES PATENTS 3,445,991 5/1969 Hanson et al ..74/l94 X Mollen ..74/l94 X Prien, Jr. ..74/194 X Primary Examiner-Leonard H. Gerin Attorney-Wheeler, House & Wheeler 57 ABSTRACT A load limiter for a self-energizing drive mechanism which has a rotating disk, a wheel driven therefrom and a swing mechanism on which the wheel is swung toward and away from the disk, said limiter comprising stop means for limiting swinging motion of the swing mechanism toward the disk and yieldable spring biased mounting means for the disk on which the disk will yield prior to engagement of the stop means, whereby the pressure between the wheel and disk is limited to the spring bias of the disk mounting means.

4 Claims, 3 Drawing Figures LOAD LIMITER FOR SELF-ENERGIZING DRIVE BACKGROUND OF THE INVENTION Copending United States application Ser. No.

101,471 filed Dec. 28, 1970, now abandoned, illus- SUMMARY OF THE INVENTION The object of the present invention is to limit the self-energizing reaction loads between the rotating disk and driven wheel in such a drive mechanism. For this purpose the invention provides suitable means for limiting'the extent of the swinging motion of the wheel toward the disk and provides for a yieldable, spring biased disk mounting on which the disk will yield prior to engagement of the stop means, whereby the pressure between the wheel and disk is limited to that imposed by the spring bias of the disk mount. The drive is selfenergizing to the extent of compressing the spring until the stop engages, but no more.

Other objects, features and advantages of the invention will appear from the following disclosure.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a reduced scale perspective view of a snow thrower which is one example of a mechanism in which the drive of the present invention can be incorporated.

FIG. 2 is an axial cross section through a portion of the snow thrower which incorporates a drive mechanism embodying the present invention.

FIG. 3 is a transverse cross section through the apparatus shown in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT I Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. The scope of the invention is defined in the claims appended hereto.

The snow thrower illustrated in FIG. 1 is for exemplification only, as the drive mechanism of the present invention can be incorporated in other apparatus. The snow thrower has an auger housing containing an auger 11 which gathers snow to the center of the auger from which it is moved rearwardly into a second stage impeller housing 12 and is thence thrown through the discharge chute 13. The snow thrower is supported and conveyed on power operated traction wheels 14. Drive and transmission mechanism within the housing 15 drives the traction wheels 14.

As' best shown in FIG. 2, and as also shown in copending United States application Ser. No. 101,471 aforesaid, one form of the drive and transmission mechanism comprises tandem axially spaced friction disks 16, 17 and an intermediate shiftable wheel 18. Disks 16, 17 are coaxial on shaft 28 and intermediate wheel 18 is mounted on swing mechanism such as a swingable gear housing 19 which pivots around the shaft 22. Wheel 18 rotates around the axis of shaft 23 in gear housing 19. The gears in housing 19 transmit the motion of the wheel 18 to the shaft 22 upon which the traction wheels 14 are mounted, as shown in FIG. 3.

Power from the snow thrower engine 24 is delivered to shaft 28 through belt 25 and pulley 26 which is formed on the periphery of disk 16. Disk 16 has a hub 27 to which shaft 28 is coupled, as by splines 29.

In accordance with the present invention, the shaft 28 carries an axially shiftable sleeve 31 which is telescopically related to the shaft 28. Sleeve 31 functions as a support means for the disk 17 which is welded thereto at 38. Shaft 28 also carries an axially fixed sleeve 32, affixed to the shaft 28 by a pin 33. The two sleeves 31, 32 have overlapping, interfitting spline forming end shoulders 34, 35. Accordingly, sleeve 31 is free to move axially on the shaft 28 but still be keyed for rotation therewith, because of the splined shoulders 34, 35.

Shaft 28 also carries a spring container cup 36 which functions as an end abutment for the coil spring 37 which has one end seated in the cup 36, and the other end against the base of the disk 17. Spring 37 is given a pre-determined resilient bias in an amount sufficient to bias the disk 17 to the left in FIG. 2 (to its broken line position) until the shoulders 34, 35 of the sleeves 31, 32 abut endwise.

Housing 15 is provided on its inside surface with a stop abutment 41 which is in the path. of movement of the turned end 43 of stop arm 42. Arm 42 is welded or otherwise attached to the swing bracket 40 which is pivotally mounted on shaft 22 and which supports the end of the shaft 23 on the opposite side of wheel 18 from gear box 19.

Gear housing 19, bracket 40 and wheel 18 are caused to swing about the axis of traction wheel shaft 22 by any suitable control mechanism. As an example, a control handle 44 is mounted on the control column 45 of the snow thrower. Handle 44 projects from a lever 46 which is pivoted on pin 47 to a bracket 48 mounted on the column 45. A control link 51 interconnects the lever 46 with a bracket arm 52 welded to the gear housing 19.

Typically there will be three positions for the control handle 44, namely, reverse, neutral and forward, in dicated by legends R, N, and F in FIGS. 1 and 2. In the reverse position the wheel 18 will be swung to engage its rubber tire 49 with the disk 16, as indicated at 49R in FIG. 2. In neutral position the tire 49 of wheel 18 will be free of engagement with both of the disks 16, 17, as indicated at 49N in FIG. 2. In forward position tire 49 of wheel 18 will engage the disk 17, as indicated at 49F in FIG. 2.

When the wheel 18 is in reverse and neutral positions, as indicated at 49R and 49N in FIG. 2, it will be out of contact with the disk 17, thus allowing the spring 37 to move the disk 17 and its sleeve 31 axially along the shaft 28 to the broken line position therein illustrated. However, as the gear box 19 is swung toward disk 17, tire 49 of wheel 18 will engage the disk 17 and begin to slide the disk 17 and its sleeve 31 axially along the axle 28 and in the direction of arrow 53. Spring 37 will yield and undergo further compression during this movement, until arm 42 reaches its full line position in FIG. 2, at which point its lateral projection 43 engages the stop abutment 41 as is also shown in FIG. 3. At this point the spring 37 has been compressed to a pre-determined amount and the pressure between the wheel 18 and disk 17 will increase no further, but will be maintained at the pre-determined setting. This setting is such that the friction load caused by the reaction of the wheel 18 against the disk 17 will not exceed a predetermined tolerable amount, but there will nevertheless be ample friction between the wheel 18 and the disk 17 to transmit all the power that is necessary to drive the traction wheels 14.

In this manner the drive will retain its self-energizing characteristics, but excessive load or drag is precluded.

We claim:

1. In a drive mechanism having a rotating disk, a wheel driven therefrom, and a swing mechanism on which said wheel is swung toward and away from said disk, the improvement for limiting the load generated by the drive mechanism as a consequence of the reaction between the disk and wheel and comprising stop means for limiting swinging motion of the swing mechanism toward said disk and yieldable resiliently biased mounting means for the disk on which the disk will yield prior to engagement of the stop means, whereby the pressure between the wheel and disk is limited to the bias of the said mounting means.

2. The invention of claim 1 in which the stop means comprises a fixed abutment and a stop arm on the swing mechanism.

3. The invention of claim 1 in which the mounting means comprises support means on which the disk is axially shiftable and a spring biasing said disk against such axial shift.

4. The invention of claim 3 in which said mounting means comprises a shaft, said support means comprising a sleeve telescoped over said shaft and a spline coupling between said shaft and sleeve.

Claims (4)

1. In a drive mechanism having a rotating disk, a wheel driven therefrom, and a swing mechanism on which said wheel is swung toward and away from said disk, the improvement for limiting the load generated by the drive mechanism as a consequence of the reaction between the disk and wheel and comprising stop means for limiting swinging motion of the swing mechanism toward said disk and yieldable resiliently biased mounting means for the disk on which the disk will yield prior to engagement of the stop means, whereby the pressure between the wheel and disk is limited to the bias of the said mounting means.

1. In a drive mechanism having a rotating disk, a wheel driven therefrom, and a swing mechanism on which said wheel is swung toward and away from said disk, the improvement for limiting the load generated by the drive mechanism as a consequence of the reaction between the disk and wheel and comprising stop means for limiting swinging motion of the swing mechanism toward said disk and yieldable resiliently biased mounting means for the disk on which the disk will yield prior to engagement of the stop means, whereby the pressure between the wheel and disk is limited to the bias of the said mounting means.

2. The invention of claim 1 in which the stop means comprises a fixed abutment and a stop arm on the swing mechanism.

3. The invention of claim 1 in which the mounting means comprises support means on which the disk is axially shiftable and a spring biasing said disk against such axial shift.

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